In the early charts and in the old tables of situations, many Islands are marked of which no other notices have come before the public. Most of these are omitted in the charts now in use, being excluded by later discoveries; and some are still retained. They possess nearly alike a kind of traditional authority; and some of them a possibility, nothing to the contrary being known, of being met with at a future period. It is therefore endeavoured here to collect them into one list.

Among the hydrographic authorities for early Discoveries in the South Sea, the one which has been most generally consulted is the Spanish chart published with the History of Commodore Anson's Voyage, in which the track of the Manila galeon is described; it being more generally known than any other early chart of the Pacific Ocean, in consequence of its being so published. On applying to it, and making the necessary examination, an extraordinary variation is found in it from other charts and from the tables then in use.

The original from which the chart in Anson was published, was a manuscript chart drawn for the use of the Spanish General of the Galeons, and, it is said, contained all the Discoveries which had at any time been made in the navigation between the Philippine Islands and New Spain.

April the 23d, 1741, in latitude 58° S, and about 10 degrees of longitude Westward of Cape Horne, in a heavy gale of wind, and in the night, the Wager frigate, commanded by David Cheap, was separated from Commodore Anson's squadron. A short time before this happened, the Wager had carried away her mizen-mast, without any sail being set on it, by a sudden and violent roll of the ship, which snapped all the chain plates to windward.

After the separation, Captain Cheap directed his course for the Island Socorro, which was the first appointed place of rendezvous. On May the 13th, in latitude between 48° and 49°; the ship was steering to the NE, with a fresh gale from the SE. The sight of birds and sea-weed indicated that the American coast was not far distant, and some uneasiness was felt at running in to make the land in stormy weather without a mizenmast. It was known to Captain Cheap that Commodore Anson intended to attack Baldivia, and most of the ordnance and military stores had been shipped in the Wager; her junction with the squadron at Socorro therefore appeared to him of material consequence, and as the coast of Chili in that latitude was believed to lay in a North and South direction, and was so drawn in the charts, no doubt was entertained of the ship being able to run off from the land at any time, if they should see occasion.

This was a Mercantile Voyage, and proved also to be a Voyage of Discovery. An abstract of a Journal kept by le Sieur Ducloz Guyot, a seaman of St. Malo, who sailed in the Leon, was communicated by M. d'Apres de Mannevillette to Mr. Dalrymple, who published it in the original French language, in his Collection of Voyages in the Southern Atlantic.

The Leon, a Spanish ship, sailed from Cadiz December the 14th, 1753. So general an eagerness for going to the Spanish Indies prevailed at that time in Spain, that the Commander of the Leon found it necessary to stop at the Island Teneriffe, to rid the ship of no less than sixty persons who had secreted themselves on board, and had kept themselves concealed, till she was clear out at sea. Nothing else occurred remarkable in the outward passage. The European cargo was disposed of in part at Valparaiso, and in part at Callao, at the latter of which places the ship lay sixteen months.

In the beginning of April, 1756, the Leon was freighted with a good homeward bound cargo, having on board her gold and silver, amounting in value to 3,260,560 dollars; 40,000 lbs. of cacao; 342 quintals of brass; 400 of block tin in bars; 440 of wool of the Peruvian sheep; 225 of bezoar; 200 of balsam; and 150 thousand weight of Jesuits bark, as well for medicine as for dying; the value of the whole estimated at, M. Duclog says, ‘22,000,000 de notre monnoye.’